Hi,
For Lower band side the formula goes this way
L>BBandBot(C,20,S,2) AND Ref(L,-1)<Ref(BBandBot(C,20,S,2),-1)
For Top band side the formula goes this way
H<BBandTop(C,20,S,2) AND Ref(H,-1)>Ref(BBandTop(C,20,S,2),-1)
Happy practicing technicals
Ajayakumar