Dropdown with - progressive disclosure with accordions vs chevrons

Question

What is the best UX for the user? Expanding the field in the same dropdown or opening a new dropdown?

The first image presents an accordion option when the user is able to preview the content in the same dropdown.

P.s. If this is the best option what should be a behavior when a user opens another section? Should other still be opened?

2. Second option presents a dropdown with a chevron. When a user clicks chevron then another dropdown with the category options expands.

What do you think is the best UX?

Answer 1

I decided to move on with option no2 - when the dropdown is reaplced with the expand content and "back" arrow. I think it's more suable than expand window. When the user wants to close it has to scroll up.

Of course, I consider large scrollable lists here. When there is a less content I would consider option no 1

Answer 2

We have done quite a bit of usability testing in this area. Most users understand the interaction the chevron is indicating so will open and expend it. However, if the list is small (i.e. with a few items) and there are not many categories, then having them open is a better experience.