Hi,
yes this is possible with SQL Custom Where, SQL Custom Where support also Content Plugin. So for example to filter users with same value of logged in users you can use something like this:

your_field_alias = '{user your_field_alias raw}'

map is composed by 3 fields, so
Map Address: {user your_field_map_alias raw}
Map Lat: {user your_field_map_alias_lat raw}
Map Lng: {user your_field_map_alias_lng raw}

Of course query to make something like this is a bit complex and you need to use in "SQL custom where" some SQL Math functions like RADIANS, COS(cosine), SIN(sine),....

Docs about SQL custom Where: http://docs.easy-profile.com/article/sql-custom-where
Docs about Content Plugin: http://docs.easy-profile.com/index.php/article/content-plugin