\definereferenceformat[inxx]  [left=( inherit ,right=),text=txt]

\setupinteraction[state=start]

\starttext
    
     \chapter[one]{xx}

     [\goto{state}[file(mk-last-state)]]
	
     [\goto{state} [file(mk-last-state)]]
	
     [\at{page} [one]]
	
     [\at{page}[one]]
	
     [\at{page}{okay}[one]]
	
     [\inxx{a}{b}[one]]
	
	[\at{page}{okay}[one]]
	
\stoptext