Step 1) Picking up a random example file from EnergyPlus in order to better explain the solution (e.g., 1ZoneDataCenterCRAC_wPumpedDXCoolingCoil.idf) you will see that the roof is under the following object:
BuildingSurface:Detailed,
Zn001:Roof001, !- Name
Roof, !- Surface Type
ROOF31, !- Construction Name
Main Zone, !- Zone Name
Outdoors, !- Outside Boundary Condition
, !- Outside Boundary Condition Object
SunExposed, !- Sun Exposure
WindExposed, !- Wind Exposure
0, !- View Factor to Ground
4, !- Number of Vertices
0.000000,15.24000,4.572, !- X,Y,Z ==> Vertex 1 {m}
0.000000,0.000000,4.572, !- X,Y,Z ==> Vertex 2 {m}
15.24000,0.000000,4.572, !- X,Y,Z ==> Vertex 3 {m}
15.24000,15.24000,4.572; !- X,Y,Z ==> Vertex 4 {m}
Step 2) ROOF31 is your roof's construction name. The object consists only of R31LAYER.
Construction,
ROOF31, !- Name
R31LAYER; !- Outside Layer
Step 3) You have to look for the R31LAYER object.
The answer is:
Material:NoMass,
R31LAYER, !- Name
Rough, !- Roughness
5.456, !- Thermal Resistance {m2-K/W}
0.9000000, !- Thermal Absorptance
0.7500000, !- Solar Absorptance
0.7500000; !- Visible Absorptance
This is where your solar and visible absorptance values are.