Not sure but I'd try to use the sources filter, and click everything except 2024 PH.
Edit just tested t, don't pk everything as there are like 400 things, but cherry pick PH 2014, tashas and it only showed legacy. If you don;t know how, click the advanced filer option, and a sources drop down will appear.
I am working with 5E and only want to see Legacy spells in my spell options.
How do I set that up?
The way it's currently implemented, you can't.
Not sure but I'd try to use the sources filter, and click everything except 2024 PH.
Edit just tested t, don't pk everything as there are like 400 things, but cherry pick PH 2014, tashas and it only showed legacy. If you don;t know how, click the advanced filer option, and a sources drop down will appear.