Extract word after specifying blank space

case 1:

Formula:

=IF(ISERROR(SEARCH(CHAR(127),SUBSTITUTE(A10," ",CHAR(127),4))),"",MID(A10,SEARCH(CHAR(127),SUBSTITUTE(A10," ",CHAR(127),2))+1,SEARCH(CHAR(127),SUBSTITUTE(A10," ",CHAR(127),3))-SEARCH(CHAR(127),SUBSTITUTE(A10," ",CHAR(127),2))))

case 2:

Formula:

=IF(ISERROR(SEARCH(CHAR(127),SUBSTITUTE(A15," ",CHAR(127),8))),"",MID(A15,SEARCH(CHAR(127),SUBSTITUTE(A15," ",CHAR(127),4))+1,SEARCH(CHAR(127),SUBSTITUTE(A15," ",CHAR(127),5))-SEARCH(CHAR(127),SUBSTITUTE(A15," ",CHAR(127),4))))

change A10 and A15 suitable.

Edit:
Formula checking spaces from left to right.
Logical test is changed to LEN(A1)-LEN(SUBSTITUTE(A1," ",""))=4 or 8
MID(...) can be defined as NAME (e.g. ShortString and LongString) in Name Manager, so formula will be shorter and clear
Maybe someone else will give you shorter solution

formula for both cases:

Formula:

=IF(LEN(A1)-LEN(SUBSTITUTE(A1," ",""))=4,MID(A1,SEARCH(CHAR(127),SUBSTITUTE(A1," ",CHAR(127),2))+1,SEARCH(CHAR(127),SUBSTITUTE(A1," ",CHAR(127),3))-SEARCH(CHAR(127),SUBSTITUTE(A1," ",CHAR(127),2))),IF(LEN(A1)-LEN(SUBSTITUTE(A1," ",""))=8,MID(A1,SEARCH(CHAR(127),SUBSTITUTE(A1," ",CHAR(127),4))+1,SEARCH(CHAR(127),SUBSTITUTE(A1," ",CHAR(127),5))-SEARCH(CHAR(127),SUBSTITUTE(A1," ",CHAR(127),4))),""))