补缺

to fill a vacancy / to make up for a shortage / to supply a deficiency

to repair / to patch / to mend / to make up for / to fill (a vacancy) / to supplement

deficiency / lack / scarce / vacant post / to run short of

to remedy omissions and correct errors (idiom)

see 拾遺補缺|拾遗补缺[shi2 yi2 bu3 que1]