Find certain text and exclude

Hello!

Can someone please help me to upgrade the following formula?

I would like to add following statement: 

“If there’s [N/A] in the job name, (blank) result in the ‘Model FCST Month Dimension’ property.

IF(ISBLANK('[FCST] Greenhouse List'.'Start Date (Offer) Dimension'),

IF(ISBLANK('[FCST] Greenhouse List'.'Manual Input'),

'[FCST] Greenhouse List'.'Forecast Start Date Dimension','[FCST] Greenhouse List'.'Manual Input'),

'[FCST] Greenhouse List'.'Start Date (Offer) Dimension')

Thanks in advance!!