Here is an AutoLISP routine that I use a lot. It is a quick way to select an object and then make a selection set of everything on that layer. I know that there is the new command in AutoCAD 2011 called “SELECT SIMILAR” but sometimes this works better for me.

The picture below shows me making a selection set of the Dimensions layer and deleting it.

1. SEL <to start>
2. Select an object on the layer to make a selection set of everything on that layer.
3. <enter> to accept that layer
4. <enter> again to make the selection set

Now everything on that layer is selected and can be edited/modified.

Note: I did not create this routine, I am just sharing it here with you…

~Enjoy

;;=============================================================

;;     Sel.lsp by Charles Alan Butler

;;   found at www.theswamp.org

;;

;;    Version 1.0 Beta  July 23,2004

;;    Version 1.1 Beta  July 13,2005

;;

;;   Creates a selection set of objects on a layer(s)

;;   User picks objects to determine the layer(s)

;;   Then User selects objects for ss or presses enter to

;;   get all objects on the selected layer(s)

;;   You may select the selection set before starting this

;;   routine. Then select the layers to keep in the set

;;=============================================================

(defun c:sel (/ ent lay ss lay:lst lay:prompt ss:first ent:lst)

;;  get anything already selected

(setq ss:first (cadr(ssgetfirst))

ss (ssadd))

;;  Get user selected layers

(if ss:first

(setq lay:prompt "\nSelect the object to choose layers to keep.")

(setq lay:prompt "\nSelect object for layer filter.")

)

(while (setq ent (entsel lay:prompt))

(setq ent:lst (cons (car ent) ent:lst))

(setq lay:lst

(cons (setq lay (cdr(assoc 8 (entget (car ent))))) lay:lst))

(prompt (strcat "\n*-* Selected Layer -> " lay))

)

;;  Un HighLite the entities

(and ent:lst (mapcar '(lambda (x) (redraw x 4)) ent:lst))

(if (> (length lay:lst) 0); got layers to work with

(progn

(setq lay "")

(setq lay:lst (vl-sort lay:lst '<)) ; removes douplicates

(foreach itm  lay:lst ; combine lay names into one , del string

(setq lay (strcat lay itm ",")))

(setq lay (substr lay 1 (1- (strlen lay)))); remove the last ,

(if ss:first ; ALREADY GOT SELECTION SET

(while (setq ent (ssname ss:first 0))

(if (member (cdr(assoc 8 (entget ent))) lay:lst)

(ssadd (ssname ss:first 0) ss)

)

(ssdel (ssname ss:first 0) ss:first)

)

(progn ; else get a selection set to work with

(prompt (strcat "\nOK >>--> Select objects for Selection set or "

"ENTER for All objects on layer(s) " lay))

;;  get objects using filter with user select

(if (null (setq ss (ssget (list (cons 8 lay)))))

;; or get ALL objects using filter

(setq ss (ssget "_X" (list (cons 8 lay))))

)

)

)

(if (> (sslength ss) 0)

(progn

(prompt (strcat "\n" (itoa (sslength ss))

" Object(s) selected on layer(s) " lay

"\nStart an ACAD command."))

(sssetfirst nil ss)

)

(prompt "\n***  Nothing Selected  ***")

)

)

)

(princ)

)

(prompt "\nSelect on Layer loaded, Enter Sel to run.")