Yes, I’m yearning for something like this. I looked into the code a bit but couldn’t figure out how to do it with a theme component and if it requires much deeper coding (aka digging into Ruby), I currently have no idea how to do that 
What I’m hoping to see is actually similar to what Circle just enabled for its platform. Here are two screenshots:
I really like the simple dropdowns and ways to filter the users. What I’ve noticed on Circle is that their search doesn’t seem to work well, so maybe Discourse could have both a stronger user search and add some additional filter options like this.
I’ve looked at many of these platforms (FB, Discord, Guilded, Circle, and others) and few seem to have good (searchable/filterable/custom-user-field/stylish) member directories. I have the User Card Directory theme component enabled and therefore I feel on the cusp of having that member directory I’ve dreamed of, just missing the filter aspect.
Would this be possible to do in a theme component with just js and CSS? Or would it require a full ruby-based plugin?