For example (see the code below)

option = { # Sell them
name = distar.3055.d
custom_tooltip = distar.3055.d.tooltip
add_monthly_resource_mult = {
resource = energy
value = @tier2materialreward
min = @tier2materialmin
max = @tier2materialmax
}
add_monthly_resource_mult = {
resource = minerals
value = @tier1materialreward
min = @tier1materialmin
max = @tier1materialmax
}
}

I should add Energy bonus and Mineral bonus and change it to Trade bonus.
Then will doing like below make the result I wish?

option = { # Sell them
name = distar.3055.d
custom_tooltip = distar.3055.d.tooltip
add_monthly_resource_mult = {
resource = trade
value = @tier2materialreward + @tier1materialreward
min = @tier2materialmin + @tier1materialmin
max = @tier2materialmax + @tier1materialmax
}
}

Or should I claim the other variable which contains Trade Value and use the codes introduced in that link?
https://stellaris.paradoxwikis.com/Variables#Manipulating_variables