Adding cost attribute :

i have specific attribute and i would like to find the path that has the lowest value of this attribute ,even if it is shortest path or longest path ,does not matter of the length .

i tried to use Cost type by one attribute ,i did not get any paths so i used by two attributes and i get output but it goes through two paths . one path has cost attribute=30 ,and the second path has cost attribute = 60 ,i did not understand why it goes through this path that contains 60 . i thought ,it will goes only through path 30 .

secondly ,i was watching videos about shortest path finder and i did the same parameter for attribute value mapper but i did not understand why should i make the parameters like that ,default value 2 ...

why will be better for Cost to use two attributes instead only one attribute ?

i need only to get one path that contains lowest cost of attribute ,how could i achieve that and does not matter of the length ?

the network is noded correctly ,because i used cost type by length and it works great .