How long is a "lunar month" in Jupiter? For Earth, the lunar month is well known. But Earth has only one moon.

But on Jupiter, how long does it takes for the same moon configuration to appear in the "sky" of the planet?

For the sake of sanity, you can consider only the four Galileian Mooons.
The three inner Galilean moons are in orbital resonances. For each orbit of Ganymede, Europa makes two orbits and Io makes four orbits.  So after 1 orbit of Ganymede, the two inner moons are in the same configuration. That is 7.154 (Earth) days.

Callisto is not in an orbital resonance, It won't be in the same position, but its orbit (of 16.689 days) is close to a ratio of 7:3 to Ganymede. So after 7 orbits of Ganymede (50.08 days) Callisto will have made just over 3 orbits (50.07 days)

If you want all known moons to be in a similar configuration you will have to wait a while, probably longer than the life of the sun (there are a lot of moons)