how to Split a part of a string only without splitting the whole string in Js

Question

var a="hi;there;my;friend;"
document.write(a.split(';'))
/*result is :
["hi","there","my","friend",""]
*/

I just want to split the character ';' for the part of the string "hi;there"and to "my;friend" and leaving the in between and the ending ';' I can make a function to do what i need but iam asking if there is easier way to do it ; and thanks