Man pages matching name xmvacreatemanagedbulletinboard in section 3:

XmVaCreateManagedBulletinBoard.3.en	debian 10 / libmotif-dev
XmVaCreateManagedBulletinBoard.3.en	debian 11 / libmotif-dev
XmVaCreateManagedBulletinBoard.3.en	debian 12 / libmotif-dev