Personnel brought in to head for bobby's beat (5)
I believe the answer is:
throb
'beat' is the definition.
(I know that throb is a more specific form of the action beat)
'personnel brought in to head for bobby's' is the wordplay.
'personnel' becomes 'HR' (Human Resources).
'brought in' means one lot of letters goes inside another.
'head for' suggests taking the first letters.
The first letter of 'bobbys' is 'b'.
'hr' put within 'to' is 'thro'.
'thro'+'b'='THROB'
(Other definitions for throb that I've seen before include "Pulsate; regular beat" , "Beat rhythmically" , "Pulse" , "Palpitate, quiver (with emotion)" , "Drum" .)