Show a Task's Comments in the Salesforce Activity Related List

To display task comment data in the Activity related list, create a custom field to store the comment text, then build a Flow to automatically copy the Comments value into that field.

Step 1: Create a Custom Field on the Activity Object

1. Navigate to Setup and search for Activity in the Quick Find box.
2. In Lightning Experience: Select the Object Manager tab, type Activity, click Activity, then select Fields & Relationships.
3. In Salesforce Classic: Type Activity into the Quick Find box and choose Activity Custom Fields.
4. Click New and choose a Text field type.
5. Enter a Field Label (e.g., "Task Comments Custom"), a Length (at least 255 characters to capture the Comments field), and a Field Name.
6. Click Next, assign the desired Profile access, then click Next again.
7. Choose the desired Page Layout (read access is required; the field does not need to appear on the layout for this workaround to function).
8. Click Save.

Step 2: Create a Record-Triggered Flow to Populate the Field

1. Navigate to Setup and type Flow into the Quick Find box.
2. Click New Flow, select Start from Scratch, click Next, then select Record-Triggered Flow and click Create.
3. Select the Task object as the trigger object.
4. Set the trigger to fire when a record is created or updated.
5. Set Entry Conditions to All Conditions are Met (AND).
6. Set the condition: Field = Description, Operator = Does Not Equal, Value = Empty String (Not Null).
7. Set "When to Run the Flow for Updated Records" to Every time a record is updated and meets the condition requirements.
8. Select Fast Field Updates as the optimization option.
9. In the Toolbox, click New Resource and set the Resource Type to Formula.
10. Enter an API name, set Data Type to Text, and paste this formula: IF(LEN({!$Record.Description})>255,LEFT({!$Record.Description},252)&"...",{!$Record.Description})
11. Click Check Syntax, then Done.
12. Create a new Update Records element, select Use the task record that triggered the Flow, set Filter Conditions to None — always update record, and map the custom field created in Step 1 to the formula resource.
13. Save and Activate the Flow.

Note: The Task Comments field is a Long Text Area that may contain more than 255 characters. This formula captures the first 255 characters and appends "..." if the content is longer. This is a known limitation of the workaround.

Step 3: Add the Custom Field to the Related List

1. Open the Page Layout of the object where you need the field displayed in the related list.
2. Scroll down to the Activity History or Open Activities related list.
3. Click the Wrench icon on the related list.
4. Locate the custom field in Available Fields, select it, and click Add.
5. Use the up/down arrow to reposition the field in the related list column order (optional).
6. Click OK and save the page layout.