This is the method I use. I treat the focus group interview transcript as the "text" and analyze it for ideas (themes) that appear again and again in the "text."
You analyse focused group interview in themes, if your group interview have many participants you group them based on how you did your interview, for example if you interviewed teachers in group you can say in school 1., teacher A said this.... another teacher said.... this was supported by a teacher A who said ..... school 2., or in groups 1, the first respondents said... Another respondents supported or argued that .... etc. group 2 group 3 etc find the group that said similar thing, during analysis you need to back it up with literature which would support or disprove your discussions. I suggest you ask your supervisor because your school might differ in their methodological approach