The filter is the blue box with the white funnel in the top section of your 1st screen shot.
Click that and you will have lots of options in there.
I tried searching like you on Android mobile with no luck. But the web search does work.
So it looks like the mobile search is not as comprehensive. I am hoping they are addressing this in the total workout search, tag, sort reboot. They are rebuilding it to be identical between all platforms.