How to make inline Listbox and button inside a div

Hy, I'm facing some issue in CSS

I am not able to arrange dropdown and then button inline.

I'm using bootstrap selectpicker so if i remove selectpicker then it is working but after adding then button is comming to the next line.

So i want to do button should come just after listbox as inline.

Here is my code

selectpicker collapse-sh" data-live-search="true" data-width="100%" data-size="5" data-actions-box="true" title="Choose one of the following...">

John

Marsh

Tony

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To check you need to include bootstrap 4 file and selectpicker css and js file.

Someone help me please i'm new in CSS.

Thanks!