Selection Filter (Lower-right corner of graphics window)

I forgot to add that when the user selects 'Part' and switches windows, the selection filter resets back to 'Geometry'.  Otherwise, this would be bearable.

You can not set the default selection. I have proposed that this be added to the software previously.

https://community.ptc.com/t5/Part-Modeling/Is-there-a-method-to-enable-custom-context-sensitive-smart/td-p/590583 

I solved this by the use of mapkeys to set the filter. This will greatly reduce mouse movement and speed things up.

Mapkeys (Creo 4 implementation)

!**** Selection Filter Control

mapkey qa @MAPKEY_LABELselection filter set annotation;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 283;

mapkey qc @MAPKEY_NAMEselection filter set curve;\
mapkey(continued) @MAPKEY_LABELselection filter set curve;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 13;

mapkey qd @MAPKEY_NAMEselection filter set datum;\
mapkey(continued) @MAPKEY_LABELselection filter set datum;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 320003;

mapkey qe @MAPKEY_NAMEselection filter set edge;\
mapkey(continued) @MAPKEY_LABELselection filter set edge;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 9;

mapkey qf @MAPKEY_NAMEselection filter set feature;\
mapkey(continued) @MAPKEY_LABELselection filter set feature;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 0;

mapkey qg @MAPKEY_NAMEselection filter set geometry;\
mapkey(continued) @MAPKEY_LABELselection filter set geometry;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 320002;

mapkey qp @MAPKEY_NAMEselection filter set part;\
mapkey(continued) @MAPKEY_LABELselection filter set part;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 4;

mapkey qq @MAPKEY_NAMEselection filter set quilts;\
mapkey(continued) @MAPKEY_LABELselection filter set quilts;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 11;

mapkey qs @MAPKEY_LABELselection filter set surface;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 5;

mapkey qv @MAPKEY_NAMEselection filter set vertex;\
mapkey(continued) @MAPKEY_LABELselection filter set vertex;\
mapkey(continued) ~ Command `ProCmdSelFilterSet` 8;

PTC specifically changed the paradigm of selection. Their concept is to give you the most direct access to useful functionality. Why do you need to select the part first? to activate it? to open it? simply select a surface of the part and the pop open Shortcut Menu give you the ability to do that based on the part you selected. You can also march up the model tree via a dropdown in that menu. Take a deeper dive into what this has given you. I really think it's like when Intent Manager (automatic dimensioning and constraining in sketcher) came into Pro/E. Most people hated it and many, including me, turned it off but as we worked with it found that it was actually exactly what we needed because it was just telling you what it was assuming, if you wanted it dimensioned differently all you did was add the dimension you want and it would refigure what it needed.

OP, if you hold down the Alt key when selecting, it disables the selection filter and you can now select parts. i find that's enough for the times when I do want to select parts, as selecting geometry usually does the trick. And the great thing with having geometry as default selection method is evident if you have large shrinkwraps in your model that would otherwise light up the entire screen whenever you passed you mouse over them. 🙂

Here's another solution that should solve your problem. Go to Options -> Selection. Here you can create your own selection filter. Make a selection filter that only contains "part". check the box to use your filter as the default selection filter. This should keep the option sticky and you don't have to change it every time you switch windows.