Nested DAX

Hi,

I'm new to the DAX community and I'm completely perplexed about how to convert my excel formulas into a DAX function that works. I have about 30 columns in my worksheet that deal with dates. I'm looking to find the business days between dates. This will exclude weekends and federal government holidays.

A variation of the excel formulas that I have are below:

1.) =IF([@[SharePointColumnA]]="",0,
IF([@[SharePointColumnD]]="",NETWORKDAYS([@[SharePointColumnA]],Current_Date,List.Holidays),
NETWORKDAYS([@[SharePointColumnA]],[@[SharePointColumnD]],List.Holidays)))

2.) =IF([@[SharePointColumnHold Start Date_1]]="",0,
IF([@[SharePointcolumnHold Start Date_1]]>[@[SharePointColumnD]],0,
IF([@[SharePointColumnHold End Date_1]]>[@[SharePointColumnD]],NETWORKDAYS([@[SharePointColumnHold Start Date_1]],[@[SharePointColumnD]],List.Holidays),
IF([@[SharePointColumnHold End Date_1]]="",NETWORKDAYS([@[SharePointColumnHold Start Date_1]],Current_Date,List.Holidays),
NETWORKDAYS([@[SharePointColumnHold Start Date_1]],[@[SharePointColumnHold End Date_1]],List.Holidays)))))

3.) =IF([@[SharePointColumnReferral Date]]="",0,
IF([@[SharePointColumnReferral Date]]>=Current_Date,0,
IF([@[SharePointColumnC]]>Current_Date,(Current_Date-[@[SharePointColumnReferral Date]])+1,
IF([@[SharePointColumnC]]="",(Current_Date-[@[SharePointColumnReferral Date]])+1,
([@[SharePointColumnC]]-[@[SharePointColumnReferral Date]])+1))))

When I tried to copy and paste these formulas into PowerBI, these fields all greyed out. Additionally, the NETWORKDAYS function is not recognized in PowerBI. Therefore, I had to do some research to find out how to create a NETWORKDAY function within Power BI. After I followed posts online. I had to modify the above formulas accordingly. These new formulas are:

1.) =IF([SharePointColumnA]="",0,

IF([SharePointColumnD]="", CALCULATE(SUM(DateTable[WORKDAY]),DATESBETWEEN(DateTable[Date],'SharePointList'[SharePointColumnA],TODAY()), 

CALCULATE(SUM(DateTable[WORKDAY]),DATESBETWEEN(DateTable[Date],'SharePointList'[SharePointColumnA],'SharePointList'[SharePointColumnD])))

ERROR MESSAGE: A function 'CALCULATE' has been used in a True/False expression that is used as a table filter expression. This is not allowed.

2.) =IF([SharePointColumnHold Start Date_1]="",0,

IF([SharePointColumnHold Start Date_1]>[SharePointColumnD],0,

IF('SharePointList'[SharePointColumnHold End Date_1]>[SharePointColumnD],CALCULATE(SUM(DateTable[WORKDAY], DATESBETWEEN (DateTable[Date], 'SharePointList'[SharePointColumnHold Start Date_1],'SharePointList'[SharePointColumnD],

IF('SharePointList'[SharePointColumnHold End Date_1]="",CALCULATE(SUM(DateTable[WORKDAY],DATESBETWEEN(DateTable[Date], 'SharePoint List'[SharePointColumnHold Start Date_1]), TODAY()),

CALCULATE(SUM(DateTable[WORKDAY]),DATESBETWEEN(DateTable[Date],'SharePointList'[SharePointColumnHold Start Date_1],'SharePointList'[SharePointColumnHold End Date_1])))

ERROR MESSGAE: Too few arguments were passed to the DATESBETWEEN function. The minimum argument count for the function is 3.

3. )=IF([SharePointColumnReferral Date]="",0,

IF([SharePointColumnReferral Date]>=TODAY(),0,
IF([SharePointColumnC]>TODAY(),(TODAY()-[SharePointColumnReferral Date])+1,
IF([SharePointColumnC]="",(TODAY()-[SharePointColumnReferral Date])+1,
([SharePointColumnC]-[SharePointColumnReferral Date])+1))))

ERROR MESSAGE: DAX comparison operations do not support comparing values of type Integer with values of type Text. Consider using the VALUE or FORMAT function to convert one of the values.

Is there someone more advanced with DAX who is willing to provide the proper syntax and formulas to help replicate the excel formulas that I listed above?  If at all possible, could you also help me identify what I did incorrectly and  provide references that are helpful for beginners? Ultimately, I'd like to look at these examples, review the solutions, read the referenced material and properly construct the other 27 columns that mirror the same logic above.

Thanks!