previous iteration in foreach

Can you give more information? You need a specific iteration, a varying one or all of them?

Not sure about the exact requirements. The following code snippet might be helpful:

a!localVariables(
  local!data: {"A","B","C","D"},
  a!forEach(
    items: local!data,
    expression: a!localVariables(
      local!previousData: if(not(fv!isFirst), index(local!data, fv!index-1), null),
      a!map(data:fv!item, previous: local!previousData)
    )
  )
)

I need to sort a list, but if there are two equal values ​​they have the same order, 
with the array
{
 name:"aaaaa", valor:2
 name:"bbbbb", valor:10
 name:"ccccc", valor:10
 name:"ddddd", valor:10
 name:"eeeee", valor:45
}
get as a result
{
 name:"aaaaa", pos:1
 name:"bbbbb", pos:2
 name:"ccccc", pos:2
 name:"ddddd", pos:2
 name:"eeeee", pos:3
}

I am trying to save the pos outside of the foreach in a local variable, or recover the value saved in pos of the previous item

I need to sort a list, but if there are two equal values ​​they have the same order,
with the array
{
name:"aaaaa", valor:2
name:"bbbbb", valor:10
name:"ccccc", valor:10
name:"ddddd", valor:10
name:"eeeee", valor:45
}
get as a result
{
name:"aaaaa", pos:1
name:"bbbbb", pos:2
name:"ccccc", pos:2
name:"ddddd", pos:2
name:"eeeee", pos:3
}

I am trying to save the pos outside of the foreach in a local variable, or recover the value saved in pos of the previous item

I did not understand what you are trying to implemented... Could you give us more information? What it would the expected output?

As Yogi Patel is sort of hinting, you can use a!foreach functions like fv!isFirst, fv!isLast, fv!item and even fv!item-1 (-x) to move around the foreach iterations, more then that you can have local variables inside local variables like shown in his code snippet, the only thing is that local variables can only ba accessed inside it's own function so the variables inside the second localVariable function won't be accessed on the 'father' local variable function

Okay, so if the valor value is same then their pos will also be same right?

This will fulfil your requirement if I understood your query correctly

a!localVariables(
  local!data: {
    a!map(
      name: "aaaaa",
      valor: 1
    ),
    a!map(
      name: "bbbbb",
      valor: 10
    ),
    a!map(
      name: "ccccc",
      valor: 10
    ),
    a!map(
      name: "ddddd",
      valor: 10
    ),
    a!map(
      name: "eeeee",
      valor: 45
    )
  },
  local!uniqueValors: union(local!data.valor, tointeger({})),
  local!valorIndices: createdictionary(
    local!uniqueValors,
    enumerate(length(local!uniqueValors))+1
  ),
  a!forEach(
    items: local!data,
    expression: a!map(
      name: fv!item.name,
      pos: property(local!valorIndices, tostring(fv!item.valor), null)
    )
  )
)

The problem with that, and please correct me if I'm wrong, is that it will only work if the 'valor' values are ordered.
In adition, never seen a 'Bean' Appian type as shown in the property function that you are using!!!!!!!!

yes for this the values should be ordered