How to select a single component in Altium Designer using the PCB filter?
Option 1:
In the properties tab, when nothing is selected, you can change the selection filter:

Enable selection of components and disable all other selections.
(Apparently this doesn't work well in single-layer mode --- disable single-layer mode before selecting a part)
Option 2:
In the PCB panel, find the component you want to select and double-click it.
This will select the part and zoom the PCB view to the part.