Decorating fabric with beads was part of the repertoire of the medieval craftsman. However evidence of it's use is much rarer than other decorative forms such as embroidery and tablet weaving (both of which it was often used in concert with), possibly because making small beads is a vast effort, and such beads are easier to unpick and reuse than thread.
Most commonly beads were either sewn individually onto fabric, or a string of beads were couched onto a fabric. Some examples exist where beads were sewn to parchment, to create a stiff backing, allowing completed beadworks to be either sewn to fabric or attached to a solid object. Beads were also strung on strings as jewelry eg. pearl necklaces, hair ornaments.
What seems conspicuously absent from preserved evidence of medieval European beading is beadwork (of more than one strand) that lacks a backing fabric. No examples of the products of bead looms, no netting work of beads, and no beads on wire contorted to form shapes such as flowers. It seems probable that at least one of the above forms was discovered in medieval times, however without evidence, we have no idea which, or what form they took.