batch to batch transfer (same material)

HI experts,

I have a scenario where i have to post the X qty from batch B ( GRN in april ) to batch A (Grn In mar) for same material.

I have consumed the material from full qty from Batch A in April and the material from batch B remained unutilized.

Now i have to consumed some more material in the month of March . Period is still open.

What is the solution as i tried batch to batch transfer using 309 but error appears "Deficit of BA :Unresticted material".

What is the alternate solution for this?