exclude rows from a slicer

I have two datasets, one with routes and one with landmarks.
The routes contain many lat / lons with timestamps, the landmarks only one set lat lon and one timestamp
Both are joined in one table
Using a slicer, i would like to filter the the routes to a particular day
This works nice, however, the landmarks are lost, as the timestamp of the landmark is outwith the slicer date
Any idea's how i could keep the landmarks in the dataset?