SASS using & for parent and that parent is first-child -

i know can specify if element has specific parent using &:

.btn {     .btn-group & {         color: blue;     } }

but can if parent btn-group , .btn-group first child?

something like:

.btn {     .btn-group & &:first-child {         color: blue;     } }

but doesn't seem work.

i worked out can do:

.btn {     .btn-group:first-child & {         color: blue;     } }

but couldn't find way have multiple pseudo selectors (except using above syntax comma separated):

// doesn't work :( .btn {     .btn-group & {         &:first-child,         &:last-child {             color: blue;         }     } }

O9