First, you have to use "{{BrowserThread}}" variable and "Element Number" command. So you can create a new variable where "[[SUBLIST_LENGTH]]" can be calculate by ([[MAIN_LIST_LENGTH]]/{{BrowserThreads}}). Lets say, you have list contains 10,000 URLs and you want to run 5 browsers threads. So "[[SUBLIST_LENGTH]]" will be (10000/5)= 2000 (check screenshot_1)
Now, you can split your MAIN_LIST in using built in variable "[[Thread Index]]" and "SUBLIST" command. (check screenshot_2)
screenshot_2.png screenshot_1.png