In Blender there is a function “Select Loop Inner-Region” where once an edge loop is selected, it will select the smallest area of the mesh completely bound by the loop (or alternatively the opposite, larger area if you select to do so).

I've been trying to figure out how to do this in Houdini? Attached is an image of an example scenario. Essentially, if that is an animated mesh (so no point re-ordering or position-based approaches), is there a way for me to select one half of it based on the selected edge loop?

Also, I would prefer not to do a timeshift/point-deform approach just to have an area selected, I'm just looking for a way to select and group part of a mesh based on a surrounding edge-loop.

Just updating this with a solution from konstantin magnus on the OD|Force forums:

Edgecusp will split your mesh in two parts.Then choose the icon “select groups or connected geometry”.

So you can take an edge loop selection or edge group and throw that as the Group parameter in the Edgecusp then you can select the portion you want with group/connected selection mode.