I’m currently doing something like that on a site I’m making.
I’m using the following code in the category view template:
[!Ditto? &startID=`212` &tagData=`categories` &tagDelimiter=`,` &tagMode=`onlyTags` &tags=[*categories*] !]
&tagData=`categories` : the TV that holds the quote’s categories, separated by commas
&tagMode=`onlyTags` : so that it matches only things that match all the categories
&tags=[*categories*] : the categories that we are looking to return. In this case held within a TV of the category view
Hope that points you in the right direction.