In linear $\ce{H_3}$ you have one MO with zero nodes, one with one node and one with two nodes. When you bend the molecule around to make a cycle, the two nodes in that last orbital merge to make a second orbital with one node. The two orbitals of cyclic $\ce{H_3}$ with one node are, of course, degenerate.

In linear $\ce{H_3}$ you have one MO with zero nodes, one with one node and one with two nodes. When you bend the molecule around to make a cycle, the two nodes in that last orbital merge to make a second orbital with one node. The two orbitals of cyclic $\ce{H_3}$ with one node are, of course, degenerate when the ring has threefold rotational symmetry.