Retrieve a value from related rows with condition

[eys2024]

I have a table "a" with columns: "matricole" (text) , "last firmware" (text)
I have a table "b" with colums: "matricola" (text), "data intervento" (date), "firmware" (text)
Tables are correlated 
In a row of table "a" I correctly see the related "box" with the rows of table "b" that are in relation
I need to set value "last firmware" of this table as value of "firmware" in table "b" in the row where the "data intervento" is the older value.
I have tried with combinations of MAX() and SELECT() functions but without results.
Thanks in advance

[TeeSee1 · Accepted solution]

LOOKUP(
 MAXROW("b","data intervento",[ref to table a]=[_THISROW])
 "b",
 "key of b",
 "firmware"
)