ISPF does not provide support to view/browse VSAM datasets - user has to have some product that does that.
ISPF only provides support to more easily drive your VSAM product. ISPF was changed so that Edit/View/Browse would give control to your VSAM
product - instead of rejecting the selection of the VSAM dataset.
EZYEDIT had similar change, to allow selection of VSAM datasets and invoke Edit/View/Browse.
That is, user is in EZYEDIT, user selects a VSAM dataset, EZYEDIT drives ISPF Edit/View/Browse service, ISPF Edit/View/Browse service invokes whatever command (REXX,CLIST or program) user defines in the ISPF configuration table.