sub replace with regex capture and modification

[mqueb]

i want to catch all text in double () and replace it with a text built with capture"
for exemple
aaa ((xyz)) bbb ((abc)) abc

yq 'sub("(?:\(\()([^\\)]+)(?:\)\))" ; "${1}" | upcase)'

i expect output to be:
aaa XYZ bbb ABC abc

but no .... it seem that nothing but string concat work as right arg of sub()

[mqueb]

i made few test:

yq '.. | select(type == "!!str" and test("\(\([^\\)]+)) |= sub("(?:\(\()([^\\)]+)(?:\)\))" ; "ff${1}ff" | upcase)'

and in output i have : aaa FFxyzFF bbb FFabcFF abc

so upcase affect all but the ${1}