You will have to create variables or Running Totals.
Almost everyine else would do this via variable formuls but here is an easy way via Running Totals (RTs).
Group on
Create a RT
Name = Address
Field To Summarize=VAL
Type = MAXIMUM
Evaluate=Use a Formula
{table.Type}='L1'
Reset=On Change of group (group1)
Next RT='City'
Exact same but change your evaluate formula to {table.Type}='CT'
Keep making RTs, one per address part you want to use.
Place these in the Group Footer1 to make sure you are getting the correct values.
Now you can create a formula using these RTs or just drop them in a text field in the Group Footer1.