I think an XPATH like this (from the current CONTROLLER2 node) should do it:

string xPath = "../preceding-sibling::tr[starts-with(td , 'ABC-')][1]/td[starts-with(. , 'ABC-')]";

It means

• get back once ancestor level up (..)
• from there, select all preceding sibling TR elements that have TD elements that start with 'ABC-'
• get the first (reverse order) of these TR.
• from this TR element, get TD elements that starts with 'ABC-'