"Hide filter" by arbitrary frontmatter properties, not just tags

[vergenzt]

What would you like to be added?

I wish I could specify a custom frontmatter property to filter by instead of only being able to filter by filename/path or tags. 🙂

Why is this needed?

I'd like to set up a context property (for personal/work/other specific projects) so that I can filter out items that aren't relevant to what situation I'm in at the moment.

It'd be nice to not have to use #tags for that so that tags can be available for other arbitrary keywords.