Dude, you're a damn rockstar! Thank you for this. Should be in core.

Having the ability to allow people to search for other members by age range is crucial in my opinion for a community type site, especially those in the dating niche. Besides the obvious reasons, no way I can expect my members to update their age every year using a generic text form field. Not sure why WordPress team isn’t putting more into Buddypress by adding features like this, guess it’s not as widely used so lower priority. I really like it so far and hope they do, and definitely add features like what your plugin offer into the core. Thanks for this plugin. On another note it also works great with the BP Profile Search plugin which is another useful plugin. Thanks!