I want to develop a feature such a way that user can select multiple options from message menu. Is it possible to select multiple options from the interactive menu at the same time ??
You can currently only select one option. Slack does not support choosing more than one option in a message.
But there are 2 alternatives:
Dialogs
Dialogs are modal and allow you to use up to 10 elements each including select menus. And they have a "submit" and "cancel" button.
This allows you to implement exactly what you are asking, but your selects would be shown in a separate Dialog window and not directly as part of your message. You also need some extra functionality to connect the Dialog with your message, e.g. by having a button in the message that opens the Dialog.
Check out this answer on how to combine slash commands, buttons and dialogs.
Chaining message with selects
Another alternative is to chain selects in multiple messages one after the other for the user. This can be done by replacing the original posted message with a new message after each user interactions.
So after the user selected the first drop down your app shows him the 2nd menu and so on. Finally you would show the user a submit or cancel button. You can of course also add some functionality to the workflow, e.g. have a cancel button for every step.
Check out this post on how to replace the current message after the user clicked on a select.
来源：https://stackoverflow.com/questions/48523512/slack-interactive-message-menu-select-multiple