Given a radius (in tile coordinates) TilemapKit should return a (mutable) list of tile GIDs in that radius.
With those GIDs one can then test each tile's properties to perhaps remove them from the list.
For instance this could be used to highlight all tiles the currently selected unit can move to in the current turn, with all blocked tiles removed. It may be helpful to get each tile's coordinate as well, for instance to be able to check if another dynamic game object occupies the tile's coordinate.