Relationship between Real Interest Rate and Employment
Recall that central banks use interest rate to control inflation by inducing spending or saving  with decrease or increase in interest rate.

Also,note the theory proposed by the short-run Phillips curve.



Though this graph has  some controversy in terms of its empirical soundness. It is the basis of how we tie interest rate to unemployment.

abstractly you can think of it as a "causal chain" being:
$$\text{interest rate}\rightarrow\text{savings rate}\rightarrow\text{spending}\rightarrow\text{inflation}\rightarrow\text{unemployment}$$

Hope this helps.