Starfleet is a military organisation, but many federation Starships and facilities have civilian personnel aboard. This is because Starfleet believes that family is important and member of Starfleet should be allowed to stay with there loved ones whilst serving aboard there vessel and bases.
II. Positions
Bartender
A ship/facility is operational 24 hours a day, and thus people are on duty around the clock, each having there free time at different times, but the recreational areas must stay open to accommodate these people. A Bar/Lounge Manager could not keep going 24 hours every day, and thus requires staff to assist him/her.
Bar/Lounge Manager
On almost every Starfleet vessel and base, there is some kind of recreational area. A place where all members of the crew can relax and enjoy, a place to forget the rigours of the day. The Bar/Lounge Manager runs such establishments for the crew.
Waiter/Waitress
Every bar, every restaurant needs some form of friendly service to help the crew relax. A warm smile who brings your food or drinks, to chat when somebody is alone or down. the Water/Waitress are theses people.
School Teacher
In the modern 24th century, many children are taught by computer holograms. However real interaction with a living person is still valued. A computer can only teach so much. The teachers responsibilities is the education of the children aboard the ship/facility. Additionally the teacher may be able to provide assistance in his/her field of specialty when required.
Barber
In the modern 24th century, many people still need to get hair cuts. This can be done by more, modern means, however real interaction with a living person is still valued. Besides, like the bartender, a barber is a good place to get advice, get something off your chest, or just talk about 'scuttlebutt' or gossip.
Other Civilians
Botanist, Chef, Messhall Attendent, Family members, Daycare Provider....etc.