Trados termbase: How to add a descriptive field to term level

I've created a termbase with 3 languages: Vietnamese, Japanese and English. I also added a descriptive field called "note" to entry level, but this field is not so useful. Now, I want to add a field named "usage" to term level so I can add example sentence to see how term can be used.

Vietnamese: Thêm trường mô tả cho mỗi thuật ngữ trong Trados
日本語：トラドス用語ベースの用語レベルに説明用フィールドを追加する方法

My Ideal: I can add 'usage' field (example sentences of usage) for each term

It should look like this:

Each term will have a field call "Usage" to add example sentences of its usage.

Entry level, Language level, Term level

Trados SDL termbase will have 3 levels:

Entry level => Language Level => Term level

You can add descriptive fields to each and all these 3 levels. In above image, I have "note" field for Entry level, and "Usage" for Term level (which I explain how to add in this article) and no descriptive fields for Language level (though I can add later as explained in this post).

Here's the flow of adding a descriptive field "Usage" to term level step by step.

Step 0: Back up your termbase first

Often in This PC > Documents > Studio 2017 > Termbases (Windows 8.1).
Just copy "***.sdltb" file to another place. No need to copy files other than .sdltb file since they will be created automatically.

Step 1: Open SDL MultiTerm >> Open termbase >> Termbase Management

Start SDL MultiTerm, open my termbase and click 'Termbase Management' then 'Definition' as above image.

I have a "Note" field for Entry level but no fields for Term level.

Step 2: Termbase wizard starts

What I want to change is "4. Add descriptive fields and specify their properties."

Step 3: Termbase Name

I don't want to change termbase name so click 'Next >'.

Step 4: Language Fields

Click 'Next >'.

Step 5: Descritives Fields

I type "Usage" in 'Field label' (or any name I desire), then click 'Add >>' button and "Usage" shows up in 'Descriptive Fileds' list in the right:

Then click 'Next >' button.

Step 6: Entry Structure

Click 'Term level' to highlight it in left panel.

Click to choose 'Usage' in the right panel:

Then click '<< Add' button while 'Term level' is still chosen in left panel to add 'Usage' to 'Term level' like this:

Step 7: Wizard Complete

Click 'Finish'.

Step 8: Alert of modification

"You have modified the termbase definition. Please verify if your user defined catalog objects are still valid."
Click 'OK'.

Step 9: Question for reloading termbase

"The termbase definition has changed. For changes to take effect, the list of termbase must be reloaded.

Reload now?"

Click 'Yes'.

Step 10: My ideal accomplished

'Add field' option appears in Term level to add 'Usage' field for each term.
(C) SGA Translation