I'm checking my tranny fluid on my car, but not sure where the 5mm bolt is to check it. I see one at the bottom of tranny, at the side, and on top under the battery.

Car is all leveled out. I removed the 6mm bolt ontop of tranny under battery, and can use a flashlight not seeing any fluid. Is that the fill port?

All help is appreciated. I saw videos online showing its the side on the drivers side, but no 5 or 6mm allen wrench looking bolts to remove, just on the passenger side, and also saw a fill port on top under air filter on other sites, but my car has nothing their either.

CVT: I use a quart pump and insert the hose into the cooler inlet or outlet located on the front-bottom of the tranny.
2002-03 cooper Midlands 5-spd trans: the fill port is on the drivers side above the axle

This doesnt pertain to you from what it sounds like, but for those DIY'ers reading:
2003-06 MCS auto: there is an E10 or E12 bolt located just to the left of the transmission range switch that you can fill slowly from the top using a funnel/hose.
2002-13 MCS 6 speed manual: 8mm allen head drain and fill plug on the passenger side of the transmission underneath and above the axle, respectively.

There are great DIY articles here on NAM which address the CVT as well. We've created one for the automatic (non-cvt) and one for the manual trans fluid replacement below:

Automatic Trans Fluid Change - R53-'06 & R52-'08

Manual Trans & Diff Fluid Change - R50-'06, R52-'08 & R53-'06