The function "Select similar" (the command SELECTSIMILAR, resp. AecSelectSimilar - see the menu Edit and the object context menu) is in older versions (pre-2011) available only in the AEC versions of AutoCAD (AutoCAD Architecture, AutoCAD MEP, AutoCAD Civil 3D).
Using a simple LISP expression you can add this functionality also to a plain AutoCAD. Add the following expression (command) to a toolbar button or context menu:
(cadr(sssetfirst nil (ssget"_X"(list(cons 0(cdr(assoc 0(entget(car(entsel"\nSelect object and all similar: "))))))))))
This function can be then used either in the normal command mode - after you select an object, all entities of the same type are grip-selected; or you can use it on the standard "Select objects" prompt - there it includes the selected object and all similar objects in a standard selection set of an editing command.
Another option is to use the expression:
(ssget(list(cons 0(cdr(assoc 0(entget(car(entsel"\nSelect object and all similar: "))))))))
This function also prompts for a sample object. Then it asks for a standard objects selection. From these objects, only those objects will be used which are similar (the same type) to the sample object.