The selection tools allow you to choose from which objects to select, based on their positions in the viewport. When you click on the selection options tool 
, ABAQUS/CAE displays the Options toolbox, and you can select the following:
Objects closest to the screen
Toggle on this tool to select only the objects closest to the front of the screen. This tool is toggled on by default.
If you toggle off this tool, ABAQUS/CAE allows you to cycle through all of the possible selections. Use the Next and Previous buttons in the prompt area to cycle forward and backward through all of the objects in the viewport that are possible selections; each object becomes highlighted in turn. For more information, see “Cycling through valid selections,” Section 6.2.6.
This filter applies to vertices, edges, faces, and cells of an ABAQUS/CAE native part and to nodes and elements of an orphan mesh.
Interior and exterior objects
Choose one of the following filters:
Select objects located both outside and inside a part.
Select only objects located on the outside of a part. In most cases this tool is selected by default.
Select only objects located on the inside of a part.