You can change it in the Victoria\db\revolt.txt file. Search for the 'BOH' tag. The provinces you grant them when you give them your independence are listed in the 'minimum = { 733 734 735 760 761 762 763 775 }'
The numbers are for the id's from the provinces you give them (to see which province has which id ingame type F12 and then 'showid' ).
The bohemian provinces are: 760 761 762 763 775
The moravian provinces are: 733 734 735
To give Bohemia only the moravian provinces when you make them independent, and give Bohemia all provinces if they get their independence by revolt change the file into:
date = { day = 1 month = january year = 1848 }
expirydate = { day = 31 month = december year = 1935 }
minimum = { 733 734 735 }
extra = { 760 761 762 763 775 }
capital = 762
culture = {
type = czech
}
religion = protestant
literacy = -1
ai = "VIP_BHO.ai"
primitive = no
revolt = yes
vassal = yes
slaves = no
This way the 3 province Bohemia will also get cores on Bohemia itself. If you don't want them to have these cores after independence, or if you don't want Bohemia to get the bohemian lands if they gain their independence after a revolt, remove the Bohemian cores from the extra:
extra = { }
Good luck with the editing