how to convert standard HTML node to JQuery?

how to convert standard HTML node to JQuery?

Inside a function:
 
mygrid._in_header_multiselect_filter=function(t,i,d){
 
I want to turn it into a JQuery version of the same so I can deal with it using JQuery, i.e. accessing it's children, setting up it's onclick event, etc.
 
How to convert it to JQuery?