SketchUp is a surface modeler, that can treat watertight volumes as “manifold solids,” for the purpose of export (or in the Pro edition, for boolean operations.)
Selection of objects is actually a different thing, so I’ll rephrase this as:
"Is there a way to limit inferences to certain categories ?"
There are some ways to modify inferencing. Clicking the SHIFT key can lock the current inference, for most native tools. (Ruby plugin tools should follow this, but some do not.)
For v2016+, the arrow keys lock the X-axis (), Y-axis (), Z-axis () or the plane ().
This is usually called something like “Osnap” or Object Snapping. (I believe SketchUp’s sister application LayOut has this.)
This (finer control) is an often requested feature. I would welcome such a feature, like a mouse-context menu where all inference snaps are checked by default, and you can uncheck those that are getting in the way of the current operation.
I might also welcome control that allows limiting inferences to only the current editing context, … such as only within the group being edited. (Again, a temporary right-click context menu item.)
I am always in favor of letting the customer use the product their way.
The following is pasted from another recent reply of mine, to another SketchUp beginner, (who seemed to not know basic geometric terms and operations. I paste it here mostly for the links.)
You usually place components, at a point (which is the origin of the component’s local axes,) with respect to some other inference point (or face) in the model. (This is called a translational transform.)
SketchUp User Guide: Finding and locking an inference
SketchUp User Guide: Knowing your inference types
SketchUp User Guide: Locking inferences with a keyboard
Then you orient the object with respect to the model’s axes, or one of the axis. (This is called a rotational transform.) In other words, you rotate objects about an axis. This is the first thing that the RotateTool wants you to indicate,… the point of this rotational axis. The second point will be the starting point for the rotational angle. The last point will be the end of the angle.
SketchUp User Guide: Flipping and Rotating
So, if you placed a fence component on the ground plane. To rotate it so that it’s longest run is lying along the green axis, you will need to rotate it about the blue (Z) axis.
You can always move it again after rotation, to snug it up against the corner of the house, etc.
SketchUp User Guide: Moving Entities Around
(FYI: The place component feature is a form of the MoveTool.) After placing a component (from the 3DW or your local components library,) just hover over this instance and you’ll see little red rotate crosses appear. If you stop over any of them, the tool switches (automagically) to the RotateTool. These rotate crosses can appear on any of the bounding box sides of the component instance. This makes it easy to immediately rotate components just after inserting them. (But you can do this at any time to component instances, using the MoveTool.)
SketchUp User Guide: Editing components
NOTE: The axes indicator lines you see displayed in the model, are initially positioned at the model origin. But they can be moved at any time, using the AxisTool. This can be handy because SketchUp’s inference engine will use them as snap lines (by the inference engine.)
SketchUp User Guide: Adjusting the Drawing Axes