calculate difference for each group

[5296]

action	feature	version	location	count	?difference?
A	f1	v1	WA	120	0
A	f1	v1	OR	110	10
A	f1	v1	CA	115	5
B	f1	v1	AZ	120	0
A	f1	v2	WA	14	1
A	f1	v2	OR	10	5
B	f1	v2	AZ	15	0

I got a table of info above: action, feature, version, location, and count.  Could anyone help me to find the last column "difference" here?  

A group is identified by same feature and version combination. so in the example table, the first four rows(f1+v1) are one group, and the last three rows(f1+v2) are the second group. 
within each group, difference = count B - count A.  
 for example:
row1, difference = count (B, f1, v1, AZ) - count (A, f1,v1,WA) = 120-120=0
row2, difference = count (B, f1, v1, AZ) - count (A, f1,v1,OR) = 120-110=10
difference of countB itself is 0.

[renjith_nair]

You may try

"Your current search"
|eventstats max(eval(if(action=="B",count,null()))) as action_b by feature,version
|eval difference=action_b - count

Run anywhere example

| makeresults |eval action="A A A B A A B"|makemv action|mvexpand action
|appendcols[|makeresults |eval feature="f1 f1 f1 f1 f1 f1 f1"|makemv feature| mvexpand feature]
|appendcols[|makeresults |eval version="v1 v1 v1 v1 v2 v2 v2"|makemv version| mvexpand version]
|appendcols[|makeresults |eval location="WA OR CA AZ WA OR AZ"|makemv location| mvexpand location]
|appendcols[|makeresults |eval count="120 110 115 120 14 10 15"|makemv count| mvexpand count]
|fields - _time
|rename COMMENT as "Ignore above data similution search"
|eventstats max(eval(if(action=="B",count,null()))) as action_b by feature,version
|eval difference=action_b - count
|fields action,feature,version,location,count,difference