Hi, I found a similar question and answers that might help at Form hash variable field value issues..

Hi Anders, thanks for the reply appreciate it. 

From the link you provided, it seems to be another problem not really related to mine.

My problem is I want to retrieve data from a form grid certain fields for the email which I used are the Email Tools. Was trying all kind of hash variable but it seems to be not working with #form or #binder

I believe it is related. If you have your grid data in another db table, then you will need to use the Hash Variable#FormDataHashVariable format like #form.tableName .fieldId [recordId]# as in the suggested answer.

I had tried but still couldn't get the data.
Can you help me to check my form design and determine what my hash variables should be?

The way the form is designed, 
Child Form (Remarks form) → contains a remarks text field and an id hidden field.

Parent Form (Approval form) → Uses a subform for the Remarks, uses a "Grid" not "Form Grid" to load the remarks history.

So the process is like this, the workflow is a Purchase Requisition workflow. The requestor will submit the PR, then it will require a manager to approve or reject. So, when the manager rejects, it will prompt him to write remarks (The remarks text field is a subform of a child form "Remarks form"). Then the outcome of the Parent Form, we have a remarks history using "Grid" not "Form Grid" just to load the remark history from the child form, the foreign key is the id hidden field of the child form. Then when the PR gets rejected it will send an email to the Requestor through the process tool (Email tools).

The purpose of these is I want to get the remarks history in the email. I am confused and not sure which hash variables format to use

Process design as shown below:

Requestor (request) → Email Notify (Tools, Email) → Manager (Activity, Approve/Reject) → If Rejected → Email Notify (Tools, Email) → End

For the #form.tableName .fieldId [recordId]# hash variable, you need to replace the tableName, fieldId and recordId with the expected values. You are essentially pointing to a specific column (fieldId) in a row (recordId) in the db table (tableName).

Thanks again for the reply. May I know what's the recordId? I couldn't find much details about it on the internet. I am using Grid not Form Grid btw.