The onset of collective rotational states as minima in the energy spectra of bosonic spinless para-H(2) (pH(2)) molecules confined in a belt around a molecular dopant is studied by analyzing excites states in (pH(2))(N)-CO(2) dusters (N <= 5). These minima result from a combined effect of a bosonic-symmetry-induced boundary periodic condition in cyclic arrangements of pH(2) and the increasingly intensified hard-core of the effective pH(2)-pH(2) interaction as N increases. The same also applies to doped (4)He clusters in a contrast with the fermionic (3)He case (N <= 4). The onset of the minima for pH(2) and (4)He marks a reversal in the apparent scaling of the rotational constant with N for the axial rotation around the dopant (from inversely proportional to proportional), whereas the (3)He counterpart retains the regular dependence. The newly developed full-configuration-interaction nuclear orbital approach for bosons is presented here for the first time.