Thanks again everybody, your thoughts are revealing (in a good way 
)
I have, for now, adopted a mixture of @TW_Tones and @CodaCoder suggestion and implemented a ‘case’ structure. Following @pmario’s suggestion about keeping it simple when creating and review once working, I will keep the multi-filter conditions for each tiddler type I am looking for and review once tiddler types have been settled.
bobj