The prefix dho means "language of". It can be attached to a nationality or speech community to imply the language of such a people. jo means "people of". The infix pa means possessive 'of'.
Dhopadhola thus means the language spoken in Padhola. Padhola is the area or region where Dhopadhola is spoken. Jopadhola is the plural of Japadhola; a person who speaks Dhopadhola. Hence, Jopadhola are speakers of Dhopadhola.
Ja is a prefix meaning the 'doer' or a person belonging to a particular place or position. The plural is Jo. That is, people who do something or belong to a particular place or organisation.
For instance Jafwonji means a teacher. Jofwonji means teachers. Jawer means a singer. Jower means singers. Janywol means a parent. Jonywol means parents. Japach means a carpenter. Jopach means carpenters.