purpose of the homebrew: an non-terrain dependent set of features that tie into the pillar of exploration and makes rangers better at ranger-related things as they level up,  it might be especially appropriate for survival-heavy campaigns where you have multiple rangers in the party, campagins where you visit a lot of terrain types (such that only getting benefits in one terrain becomes useless) or where the entire campaign takes place in a single terrain type (where natural explorer becomes a lot more potent and where you would gain absolutely no benefits from favoured terrain choices beyond the first).

This is a rough draft, slightly overtuned, listed roughly in the order that i came up with them

Skilled Explorer (replaces Natural Explorer) you have specialized in certain talents. You gain one of the listed benefits of your choice at 1st, 6th and 10th level.

Tracker: you have a special knack for tracking, gaining the following benefits:
- your proficiency bonus is doubled for wisdom (survival) checks made to track, and you may treat a roll of 7 or lower for a wisdom (survival) check as a roll of 8
- While tracking other creatures, you also learn their exact number, their sizes, and how long ago they passed through the area.
- while traveling alone, you can track at fast pace

Guide: you have a knack for keeping the group together and gain the following benefits::
- while traveling for an hour or more, difficult terrain does not slow your groups travel
- your group cannot become lost through non magical means
- when the entire group is forced to make an abillity check or saving throw, other members of the group may use your dice roll instead of their own if theirs is lower 
- your group can travel for 1 hour more per day without risking exhaustion

Perceptive: you are good at noticing hidden danger, gaining the following benefits:
- you have advantage on all wisdom (perception) checks
- even when engaged in another activity, you remain alert to danger
- you have advantage on initiative checks

Supplier: no adventuring party runs on an empty stomach, and you make sure that the group is fed, you gain the following benefits:
- your proficiency bonus is doubled for wisdom (survival) checks made to forage, wisdom (medicine) checks made to stabilize a dying creature, as well as on all intelegence and wisdom based checks that use your proficiency in cook's utensils or the herbalisim kit
- when you forage, you find twice as much food as you normally would
- by special means of preparing food, you can have 4 days of rations fully feed a creature every day for 5 days
- when creatures taking a short rest consume food you prepare, they may reroll each hit dice they spend during the rest and take the higher result, and creatures who would regain hit points above their hit point maximum from spending hit dice can keep excess hit points as temporary hit points. A creature cannot gain more temporary hit points than twice their level this way.

Subtle Traveler: You are particularly skilled at traveling through the wilderness without being noticed, and thus you gain the following benefits:
- whenever you make a dexterity (stealth) check while moving stealthily for an hour or more you may treat a roll of 7 or lower as 8
- you can move stealthily at normal pace
- you can attempt to hide even when only lightly obscured by natural phenomena
- other creatures have disadvantage on wisdom (survival) checks made to track your group

Spirit Whisperer (prerequisite: 10th level): you learn to listen to the gossip that the local nature spirits tell you.
- immediately after you finish a long rest, you can spend 10 minutes to have the local spirits teach you a new spell, wich counts as a ranger spell to you and does not count against the number of ranger spells you know. Your knowledge of this new spell lasts until the end of your next long rest. The spell you choose must be a 1st level druid spell, or a spell on the list of circle spells corresponding to the terrain you are in as per the circle of the land subclass (so for instance a ranger who finishes a long rest in the arctic terrain could prepare hold person or any other spell from the arctic druid while a ranger who finishes a long rest in the underdark could prepare web or spider climb).
- whenever you use the primeval awareness feature using a spell slot of 3rd level or higher, you also learn your aproximate distance to the nearest individual creature of each creature type you detect

Knowledgable: you have a lot of knowledge regarding geography and creatures, and gain the following benefits as a result:
- your proficiency bonus is doubled for intelegence (nature) checks, as well as for checks made to navigate and all intelegence check using your proficiency with cartographers tools and navigator's tools.
- you can recall any path you have traveled and uncannily know the fastest path to a settled area (fastest path does not nessesarily mean the easiest, safest or closest path, just that it is what will take you to some kind of settled area the fastest)
- by spending 1 minute studying a creature, you can determine if it is native to the local area and if it or any of its ancestors was native to this plane of existence. You also gain andvantage on int checks to recall lore about and wisdom (survival) checks made to track it and it's kin for the next 4 hours or until you use this feature again
- when you use primeval awareness, you can determine your distance to the nearest monster lair within 1 mile

Survivor: you know how to deal with anything the natural world can throw at you, and gain the following benefits as a result:
- you are considered naturally adapted to heights as high as 20 000 feet
- you are immune to extreme heat and extreme cold
- you are automatically aware of any wilderness hazard within 10 feet of you
- you can engage in a special type of travel activity, "warding off hazards". While you do, your group has advantage on saving throws against natural hazards and resistance to damage dealt by such hazards

I'll have to come back later to check this out because this is something that I've been looking into as well but after a brief skim, one thing that stood out the me is for Subtle traveler. The "you can move stealthily at normal pace" snippet has the same issue that I have with favored terrain, where you know have a feature that you can only use when you're alone. I'd personally would do it as a "small group" such as you and 3-5 other creatures, and possibly add snippet about "if playing as a beastmaster then..." you don't get screwed out of that since the errata specifically stated the stealth part for your favored terrain.