Devmargi means, a person who is on the path of Devas.
Dev means one who gives something to us.
Eeswhar (God) is my Dev.
Parents and ancestors are my devas.
Other loved ones are also devas such as brother, spouse, relatives and some friends etc.
The powers which are directly or indirectly helping us are devas.
Power of nature, such as sun, moon, wind etc. are devas. Following their qualities are going on the path of them.