I have created a custom list named “K2 Workflow Tutorials” in which K2 workflow will be created for creating new folder. Folder will be created in the custom list named “K2 Workflow List”. Please refer my previous article to create a K2 workflow in SharePoint 2013 Online.
Go to K2 designer, drag and drop Create Folder step from the List Item workflow steps in the ribbon interface.
Specify the site collection where the folder has to be created and specify the name for the folder. Click on Next button.
Specify the destination list where the folder has to be created and then click on Finish button.
Deploy the workflow. Create a list item in “K2 Workflow Tutorials”. After few minutes the workflow will be completed and the folder (Name of the folder will be list item “Title” field value) will be created in the “K2 Workflow List” list.