By using the BluetoothLEAdvertisementFilter class on the Watcher you can select only to receive advertisements events for your devices.
The sample shows how to filter adrvertisements by whole advertisement data sections or just a few bytes within a data section to filter advertisements received by the watcher event handler.
Also how to set up a signal strength filter to only receive advertisements from near devices.
See main Bluetooth sample's readme for more information.
The sample is located here.