I DM a campaign and have a master subscription.  I have enabled content sharing, and I have all the core books + SCAG. One of the players has XGE. 

I see XGE in sources and am able to view it, etc.

However, when attempting to create an NPC I'm unable to select options from XGE. I have tried both the character builder and "create unassigned character" under campaign manager .

Per the following, it sounds like I should be able to: https://dndbeyond.zendesk.com/hc/en-us/articles/115011257067-Campaign-Content-Sharing-and-You

You should be able to use the options when creating unassigned character. Try turning sharing off and on again, then retry.

(You won't have access to paid character options you didn't buy yourself outside of a campaign)

Quote from DxJxC >>

You should be able to use the options when creating unassigned character. Try turning sharing off and on again, then retry.

(You won't have access to paid character options you didn't buy yourself outside of a campaign)

 Thanks...I went back through and it works now!

Wish I could "hide" these characters since it is an unfriendly NPC.  I guess the only way to do that would be to buy XGE for myself.

Once you create it, removing it from the campaign should leave its options alone. You just can't change or add options you don't own.